Grain processing facilities, such as a commercial livestock feed mill, typically have a central processing area and several bulk grain storage bins. Grain flows from these bins into the processing area either by gravity or through augers that draw grain from the bottoms of the bulk bins. In either case, the flow rate of the grain from the various sources is quite variable. It is not uncommon for there to be as much as 100 percent variation between the highest and lowest grain flow rates within a particular facility.
The first automated grain conditioning apparatus was designed to monitor and adjust the moisture content of a single grain entering a processing area, where the flow rate of the grain was assumed to be relatively constant. When more than one grain flow rate was encountered, various manual adjustments were made to control the signal to produce the desired result. This approach worked, but was entirely empirical, and produced a less than fully automated system. The apparatus had a capability to adjust the amount of moisture added to the incoming grain only according to changes in the moisture content of the grain. The apparatus had no capability to track and adjust for any changes in the mass flow rate. If an individual grain source changed flow rate after the initial calibration, or if there were variations in grain flow during operation, there was no automatic adjustment of the amount of moisture being added.